/*
 * Copyright (C) 2004, 2005, 2006 Joe Walnes.
 * Copyright (C) 2006, 2007, 2008, 2009, 2011, 2014, 2015, 2018 XStream Committers.
 * All rights reserved.
 *
 * The software in this package is published under the terms of the BSD
 * style license a copy of which has been included with this distribution in
 * the LICENSE.txt file.
 *
 * Created on 07. March 2004 by Joe Walnes
 */
package com.feilong.lib.xstream.io.xml;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.FactoryConfigurationError;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import com.feilong.lib.xstream.converters.reflection.ObjectAccessException;
import com.feilong.lib.xstream.core.JVM;
import com.feilong.lib.xstream.io.HierarchicalStreamReader;
import com.feilong.lib.xstream.io.HierarchicalStreamWriter;
import com.feilong.lib.xstream.io.StreamException;
import com.feilong.lib.xstream.io.naming.NameCoder;

public class DomDriver extends AbstractXmlDriver{

    private final String           encoding;

    private DocumentBuilderFactory documentBuilderFactory;

    /**
     * Construct a DomDriver.
     */
    public DomDriver(){
        this(null);
    }

    /**
     * Construct a DomDriver with a specified encoding. The created DomReader will ignore any
     * encoding attribute of the XML header though.
     */
    public DomDriver(String encoding){
        this(encoding, new XmlFriendlyNameCoder());
    }

    /**
     * @since 1.4
     */
    public DomDriver(String encoding, NameCoder nameCoder){
        super(nameCoder);
        this.encoding = encoding;
    }

    @Override
    public HierarchicalStreamReader createReader(Reader in){
        return createReader(new InputSource(in));
    }

    @Override
    public HierarchicalStreamReader createReader(InputStream in){
        return createReader(new InputSource(in));
    }

    @Override
    public HierarchicalStreamReader createReader(URL in){
        return createReader(new InputSource(in.toExternalForm()));
    }

    @Override
    public HierarchicalStreamReader createReader(File in){
        return createReader(new InputSource(in.toURI().toASCIIString()));
    }

    private HierarchicalStreamReader createReader(InputSource source){
        try{
            if (documentBuilderFactory == null){
                synchronized (this){
                    if (documentBuilderFactory == null){
                        documentBuilderFactory = createDocumentBuilderFactory();
                    }
                }
            }
            final DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
            if (encoding != null){
                source.setEncoding(encoding);
            }
            Document document = documentBuilder.parse(source);
            return new DomReader(document, getNameCoder());
        }catch (FactoryConfigurationError e){
            throw new StreamException(e);
        }catch (ParserConfigurationException e){
            throw new StreamException(e);
        }catch (SAXException e){
            throw new StreamException(e);
        }catch (IOException e){
            throw new StreamException(e);
        }
    }

    @Override
    public HierarchicalStreamWriter createWriter(Writer out){
        return new PrettyPrintWriter(out, getNameCoder());
    }

    @Override
    public HierarchicalStreamWriter createWriter(OutputStream out){
        try{
            return createWriter(encoding != null ? new OutputStreamWriter(out, encoding) : new OutputStreamWriter(out));
        }catch (UnsupportedEncodingException e){
            throw new StreamException(e);
        }
    }

    /**
     * Create the DocumentBuilderFactory instance.
     * 
     * @return the new instance
     * @since 1.4.9
     */
    protected DocumentBuilderFactory createDocumentBuilderFactory(){
        final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        if (JVM.isVersion(5)){
            try{
                Method method = DocumentBuilderFactory.class.getMethod("setFeature", new Class[] { String.class, boolean.class });
                method.invoke(factory, new Object[] { "http://apache.org/xml/features/disallow-doctype-decl", Boolean.TRUE });
            }catch (NoSuchMethodException e){
                // Ignore
            }catch (IllegalAccessException e){
                throw new ObjectAccessException("Cannot set feature of DocumentBuilderFactory.", e);
            }catch (InvocationTargetException e){
                Throwable cause = e.getCause();
                if (JVM.isVersion(6) || (cause instanceof ParserConfigurationException
                                && cause.getMessage().indexOf("disallow-doctype-decl") < 0)){
                    throw new StreamException(cause);
                }
            }
        }
        factory.setExpandEntityReferences(false);
        return factory;
    }
}
